Physicists announced on Wednesday that they have discovered the most convincing evidence yet of the existence of dark matter – the particles that are thought to make up a quarter of the universe but whose presence has never been confirmed.

Members of an international team gathered at Nasa in Washington and Cern in Switzerland to report their findings, which come from a $2bn particle detector mounted to the International Space Station.

Chinese scientists say they have developed the world's lightest material, lighter than air, which could play an important role in tackling pollution.

The material dubbed graphene aerogel or carbon aerogel, developed at Zhejiang University in Hangzhou, weighs just 0.16 milligrams per cubic centimeter, a sixth that of air, China's state-run Xinhua News Agency reported Friday.

The material, derived from a gel with the liquid component replaced by a gas, is easy to manufacture and has strong oil-absorption properties, its developer says.

New results from looking at the split-second after the Big Bang indicate the universe is 80 million years older than previously thought and provide ancient evidence supporting core concepts about the cosmos — how it began, what it’s made of and where it’s going.

The findings released Thursday bolster a key theory called inflation, which says the universe burst from subatomic size to its now-observable expanse in a fraction of a second. The new observations from the European Space Agency’s $900 million Planck space probe appear to reinforce some predictions made decades ago solely on the basis of mathematical concepts.

The Voyager-1 probe has left the Solar System, according to some scientists. If confirmed, it would be the first man-made object to do so. Launched in September 1977, the probe was sent initially to study the outer planets, but then just kept on going.

Researchers who have studied its data indicate it has now entered a realm of space beyond the influence of our Sun. But the US space agency (Nasa) says there is still some doubt about this.

The search is all but over for a subatomic particle that is a crucial building block of the universe.

Physicists announced Thursday they believe they have discovered the subatomic particle predicted nearly a half-century ago, which will go a long way toward explaining what gives electrons and all matter in the universe size and shape.

U.S. astronomers say detailed observation of four planets orbiting a star relatively close to the sun has revealed them to be among the most exotic ones known.

The researchers said the findings were made possible by a first-of-its-kind telescope imaging system that allowed the astronomers to pick out the planets amidst the bright glare of their parent star and measure their spectra, the rainbows of light that reveal the chemical signatures of planetary atmospheres.

An ancient network of rivers on Mars once made parts of the planet habitable for microbial life, according to the latest analysis from Nasa's Curiosity rover.

Rock dust drilled from sediments in the giant Gale crater on the red planet were found to contain clay minerals that can have formed only in water, scientists said.The discovery of other substances alongside the clays, such as calcium phosphate, suggest the soil was neutral or mildly alkaline, making the environment suitable for microbes.